/*****************************************************************************
 * libvlc.h:  libvlc external API
 *****************************************************************************
 * Copyright (C) 1998-2009 VLC authors and VideoLAN
 * $Id: 485f4ff7198fd86d7935613b254f074f47577dd5 $
 *
 * Authors: Clément Stenac <zorglub@videolan.org>
 *          Jean-Paul Saman <jpsaman@videolan.org>
 *          Pierre d'Herbemont <pdherbemont@videolan.org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/**
 * \file
 * This file defines libvlc external API
 */

/**
 * \defgroup libvlc LibVLC
 * LibVLC is the external programming interface of the VLC media player.
 * It is used to embed VLC into other applications or frameworks.
 * @{
 */

#ifndef VLC_LIBVLC_H
#define VLC_LIBVLC_H 1

#if defined (_WIN32) && defined (DLL_EXPORT)
# define LIBVLC_API __declspec(dllexport)
#elif defined (__GNUC__) && (__GNUC__ >= 4)
# define LIBVLC_API __attribute__((visibility("default")))
#else
# define LIBVLC_API
#endif

#ifdef __LIBVLC__
/* Avoid unhelpful warnings from libvlc with our deprecated APIs */
#   define LIBVLC_DEPRECATED
#elif defined(__GNUC__) && \
      (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
# define LIBVLC_DEPRECATED __attribute__((deprecated))
#else
# define LIBVLC_DEPRECATED
#endif

#include <stdio.h>
#include <stdarg.h>

# ifdef __cplusplus
extern "C" {
# endif

#include <vlc/libvlc_structures.h>

    /** \defgroup libvlc_core LibVLC core
     * \ingroup libvlc
     * Before it can do anything useful, LibVLC must be initialized.
     * You can create one (or more) instance(s) of LibVLC in a given process,
     * with libvlc_new() and destroy them with libvlc_release().
     *
     * \version Unless otherwise stated, these functions are available
     * from LibVLC versions numbered 1.1.0 or more.
     * Earlier versions (0.9.x and 1.0.x) are <b>not</b> compatible.
     * @{
     */

    /** \defgroup libvlc_error LibVLC error handling
     * @{
     */

    /**
     * A human-readable error message for the last LibVLC error in the calling
     * thread. The resulting string is valid until another error occurs (at least
     * until the next LibVLC call).
     *
     * @warning
     * This will be NULL if there was no error.
     */
    LIBVLC_API const char *libvlc_errmsg (void);

    /**
     * Clears the LibVLC error status for the current thread. This is optional.
     * By default, the error status is automatically overridden when a new error
     * occurs, and destroyed when the thread exits.
     */
    LIBVLC_API void libvlc_clearerr (void);

    /**
     * Sets the LibVLC error status and message for the current thread.
     * Any previous error is overridden.
     * \param fmt the format string
     * \param ap the arguments
     * \return a nul terminated string in any case
     */
    LIBVLC_API const char *libvlc_vprinterr (const char *fmt, va_list ap);

    /**
     * Sets the LibVLC error status and message for the current thread.
     * Any previous error is overridden.
     * \param fmt the format string
     * \param args the arguments
     * \return a nul terminated string in any case
     */
    LIBVLC_API const char *libvlc_printerr (const char *fmt, ...);

    /**@} */

    /**
     * Create and initialize a libvlc instance.
     * This functions accept a list of "command line" arguments similar to the
     * main(). These arguments affect the LibVLC instance default configuration.
     *
     * \version
     * Arguments are meant to be passed from the command line to LibVLC, just like
     * VLC media player does. The list of valid arguments depends on the LibVLC
     * version, the operating system and platform, and set of available LibVLC
     * plugins. Invalid or unsupported arguments will cause the function to fail
     * (i.e. return NULL). Also, some arguments may alter the behaviour or
     * otherwise interfere with other LibVLC functions.
     *
     * \warning
     * There is absolutely no warranty or promise of forward, backward and
     * cross-platform compatibility with regards to libvlc_new() arguments.
     * We recommend that you do not use them, other than when debugging.
     *
     * \param argc the number of arguments (should be 0)
     * \param argv list of arguments (should be NULL)
     * \return the libvlc instance or NULL in case of error
     */
    LIBVLC_API libvlc_instance_t *
    libvlc_new( int argc , const char *const *argv );

    /**
     * Decrement the reference count of a libvlc instance, and destroy it
     * if it reaches zero.
     *
     * \param p_instance the instance to destroy
     */
    LIBVLC_API void libvlc_release( libvlc_instance_t *p_instance );

    /**
     * Increments the reference count of a libvlc instance.
     * The initial reference count is 1 after libvlc_new() returns.
     *
     * \param p_instance the instance to reference
     */
    LIBVLC_API void libvlc_retain( libvlc_instance_t *p_instance );

    /**
     * Try to start a user interface for the libvlc instance.
     *
     * \param p_instance the instance
     * \param name interface name, or NULL for default
     * \return 0 on success, -1 on error.
     */
    LIBVLC_API
    int libvlc_add_intf( libvlc_instance_t *p_instance, const char *name );

    /**
     * Registers a callback for the LibVLC exit event. This is mostly useful if
     * the VLC playlist and/or at least one interface are started with
     * libvlc_playlist_play() or libvlc_add_intf() respectively.
     * Typically, this function will wake up your application main loop (from
     * another thread).
     *
     * \note This function should be called before the playlist or interface are
     * started. Otherwise, there is a small race condition: the exit event could
     * be raised before the handler is registered.
     *
     * \param p_instance LibVLC instance
     * \param cb callback to invoke when LibVLC wants to exit,
     *           or NULL to disable the exit handler (as by default)
     * \param opaque data pointer for the callback
     * \warning This function and libvlc_wait() cannot be used at the same time.
     */
    LIBVLC_API
    void libvlc_set_exit_handler( libvlc_instance_t *p_instance,
                                  void (*cb) (void *), void *opaque );

    /**
     * Waits until an interface causes the instance to exit.
     * You should start at least one interface first, using libvlc_add_intf().
     *
     * \param p_instance the instance
     * \warning This function wastes one thread doing basically nothing.
     * libvlc_set_exit_handler() should be used instead.
     */
    LIBVLC_DEPRECATED LIBVLC_API
    void libvlc_wait( libvlc_instance_t *p_instance );

    /**
     * Sets the application name. LibVLC passes this as the user agent string
     * when a protocol requires it.
     *
     * \param p_instance LibVLC instance
     * \param name human-readable application name, e.g. "FooBar player 1.2.3"
     * \param http HTTP User Agent, e.g. "FooBar/1.2.3 Python/2.6.0"
     * \version LibVLC 1.1.1 or later
     */
    LIBVLC_API
    void libvlc_set_user_agent( libvlc_instance_t *p_instance,
                                const char *name, const char *http );

    /**
     * Sets some meta-informations about the application.
     * See also libvlc_set_user_agent().
     *
     * \param p_instance LibVLC instance
     * \param id Java-style application identifier, e.g. "com.acme.foobar"
     * \param version application version numbers, e.g. "1.2.3"
     * \param icon application icon name, e.g. "foobar"
     * \version LibVLC 2.1.0 or later.
     */
    LIBVLC_API
    void libvlc_set_app_id( libvlc_instance_t *p_instance, const char *id,
                            const char *version, const char *icon );

    /**
     * Retrieve libvlc version.
     *
     * Example: "1.1.0-git The Luggage"
     *
     * \return a string containing the libvlc version
     */
    LIBVLC_API const char *libvlc_get_version(void);

    /**
     * Retrieve libvlc compiler version.
     *
     * Example: "gcc version 4.2.3 (Ubuntu 4.2.3-2ubuntu6)"
     *
     * \return a string containing the libvlc compiler version
     */
    LIBVLC_API const char *libvlc_get_compiler(void);

    /**
     * Retrieve libvlc changeset.
     *
     * Example: "aa9bce0bc4"
     *
     * \return a string containing the libvlc changeset
     */
    LIBVLC_API const char *libvlc_get_changeset(void);

    /**
     * Frees an heap allocation returned by a LibVLC function.
     * If you know you're using the same underlying C run-time as the LibVLC
     * implementation, then you can call ANSI C free() directly instead.
     *
     * \param ptr the pointer
     */
    LIBVLC_API void libvlc_free( void *ptr );

    /** \defgroup libvlc_event LibVLC asynchronous events
     * LibVLC emits asynchronous events.
     *
     * Several LibVLC objects (such @ref libvlc_instance_t as
     * @ref libvlc_media_player_t) generate events asynchronously. Each of them
     * provides @ref libvlc_event_manager_t event manager. You can subscribe to
     * events with libvlc_event_attach() and unsubscribe with
     * libvlc_event_detach().
     * @{
     */

    /**
     * Event manager that belongs to a libvlc object, and from whom events can
     * be received.
     */
    typedef struct libvlc_event_manager_t libvlc_event_manager_t;

    struct libvlc_event_t;

    /**
     * Type of a LibVLC event.
     */
    typedef int libvlc_event_type_t;

    /**
     * Callback function notification
     * \param p_event the event triggering the callback
     */
    typedef void ( *libvlc_callback_t )( const struct libvlc_event_t *, void * );

    /**
     * Register for an event notification.
     *
     * \param p_event_manager the event manager to which you want to attach to.
     *        Generally it is obtained by vlc_my_object_event_manager() where
     *        my_object is the object you want to listen to.
     * \param i_event_type the desired event to which we want to listen
     * \param f_callback the function to call when i_event_type occurs
     * \param user_data user provided data to carry with the event
     * \return 0 on success, ENOMEM on error
     */
    LIBVLC_API int libvlc_event_attach( libvlc_event_manager_t *p_event_manager,
                                        libvlc_event_type_t i_event_type,
                                        libvlc_callback_t f_callback,
                                        void *user_data );

    /**
     * Unregister an event notification.
     *
     * \param p_event_manager the event manager
     * \param i_event_type the desired event to which we want to unregister
     * \param f_callback the function to call when i_event_type occurs
     * \param p_user_data user provided data to carry with the event
     */
    LIBVLC_API void libvlc_event_detach( libvlc_event_manager_t *p_event_manager,
                                         libvlc_event_type_t i_event_type,
                                         libvlc_callback_t f_callback,
                                         void *p_user_data );

    /**
     * Get an event's type name.
     *
     * \param event_type the desired event
     */
    LIBVLC_API const char *libvlc_event_type_name( libvlc_event_type_t event_type );

    /** @} */

    /** \defgroup libvlc_log LibVLC logging
     * libvlc_log_* functions provide access to the LibVLC messages log.
     * This is used for logging and debugging.
     * @{
     */

    /**
     * Logging messages level.
     * \note Future LibVLC versions may define new levels.
     */
    enum libvlc_log_level {
        LIBVLC_DEBUG = 0, /**< Debug message */
        LIBVLC_NOTICE = 2, /**< Important informational message */
        LIBVLC_WARNING = 3, /**< Warning (potential error) message */
        LIBVLC_ERROR = 4  /**< Error message */
    };

    typedef struct vlc_log_t libvlc_log_t;

    /**
     * Gets debugging informations about a log message: the name of the VLC module
     * emitting the message and the message location within the source code.
     *
     * The returned module name and file name will be NULL if unknown.
     * The returned line number will similarly be zero if unknown.
     *
     * \param ctx message context (as passed to the @ref libvlc_log_cb callback)
     * \param module module name storage (or NULL) [OUT]
     * \param file source code file name storage (or NULL) [OUT]
     * \param line source code file line number storage (or NULL) [OUT]
     * \warning The returned module name and source code file name, if non-NULL,
     * are only valid until the logging callback returns.
     *
     * \version LibVLC 2.1.0 or later
     */
    LIBVLC_API void libvlc_log_get_context(const libvlc_log_t *ctx,
                                           const char **module, const char **file, unsigned *line);

    /**
     * Gets VLC object informations about a log message: the type name of the VLC
     * object emitting the message, the object header if any and a temporaly-unique
     * object identifier. These informations are mainly meant for <b>manual</b>
     * troubleshooting.
     *
     * The returned type name may be "generic" if unknown, but it cannot be NULL.
     * The returned header will be NULL if unset; in current versions, the header
     * is used to distinguish for VLM inputs.
     * The returned object ID will be zero if the message is not associated with
     * any VLC object.
     *
     * \param ctx message context (as passed to the @ref libvlc_log_cb callback)
     * \param name object name storage (or NULL) [OUT]
     * \param header object header (or NULL) [OUT]
     * \param line source code file line number storage (or NULL) [OUT]
     * \warning The returned module name and source code file name, if non-NULL,
     * are only valid until the logging callback returns.
     *
     * \version LibVLC 2.1.0 or later
     */
    LIBVLC_API void libvlc_log_get_object(const libvlc_log_t *ctx,
                                          const char **name, const char **header, uintptr_t *id);

    /**
     * Callback prototype for LibVLC log message handler.
     * \param data data pointer as given to libvlc_log_set()
     * \param level message level (@ref enum libvlc_log_level)
     * \param ctx message context (meta-informations about the message)
     * \param fmt printf() format string (as defined by ISO C11)
     * \param args variable argument list for the format
     * \note Log message handlers <b>must</b> be thread-safe.
     * \warning The message context pointer, the format string parameters and the
     *          variable arguments are only valid until the callback returns.
     */
    typedef void (*libvlc_log_cb)(void *data, int level, const libvlc_log_t *ctx,
                                  const char *fmt, va_list args);

    /**
     * Unsets the logging callback for a LibVLC instance. This is rarely needed:
     * the callback is implicitly unset when the instance is destroyed.
     * This function will wait for any pending callbacks invocation to complete
     * (causing a deadlock if called from within the callback).
     *
     * \param p_instance libvlc instance
     * \version LibVLC 2.1.0 or later
     */
    LIBVLC_API void libvlc_log_unset( libvlc_instance_t * );

    /**
     * Sets the logging callback for a LibVLC instance.
     * This function is thread-safe: it will wait for any pending callbacks
     * invocation to complete.
     *
     * \param cb callback function pointer
     * \param data opaque data pointer for the callback function
     *
     * \note Some log messages (especially debug) are emitted by LibVLC while
     * is being initialized. These messages cannot be captured with this interface.
     *
     * \warning A deadlock may occur if this function is called from the callback.
     *
     * \param p_instance libvlc instance
     * \version LibVLC 2.1.0 or later
     */
    LIBVLC_API void libvlc_log_set( libvlc_instance_t *,
                                    libvlc_log_cb cb, void *data );


    /**
     * Sets up logging to a file.
     * \param p_instance libvlc instance
     * \param stream FILE pointer opened for writing
     *         (the FILE pointer must remain valid until libvlc_log_unset())
     * \version LibVLC 2.1.0 or later
     */
    LIBVLC_API void libvlc_log_set_file( libvlc_instance_t *, FILE *stream );

    /**
     * Always returns minus one.
     * This function is only provided for backward compatibility.
     *
     * \param p_instance ignored
     * \return always -1
     */
    LIBVLC_DEPRECATED LIBVLC_API
    unsigned libvlc_get_log_verbosity( const libvlc_instance_t *p_instance );

    /**
     * This function does nothing.
     * It is only provided for backward compatibility.
     *
     * \param p_instance ignored
     * \param level ignored
     */
    LIBVLC_DEPRECATED LIBVLC_API
    void libvlc_set_log_verbosity( libvlc_instance_t *p_instance, unsigned level );

    /**
     * This function does nothing useful.
     * It is only provided for backward compatibility.
     *
     * \param p_instance libvlc instance
     * \return an unique pointer or NULL on error
     */
    LIBVLC_DEPRECATED LIBVLC_API
    libvlc_log_t *libvlc_log_open( libvlc_instance_t *p_instance );

    /**
     * Frees memory allocated by libvlc_log_open().
     *
     * \param p_log libvlc log instance or NULL
     */
    LIBVLC_DEPRECATED LIBVLC_API
    void libvlc_log_close( libvlc_log_t *p_log );

    /**
     * Always returns zero.
     * This function is only provided for backward compatibility.
     *
     * \param p_log ignored
     * \return always zero
     */
    LIBVLC_DEPRECATED LIBVLC_API
    unsigned libvlc_log_count( const libvlc_log_t *p_log );

    /**
     * This function does nothing.
     * It is only provided for backward compatibility.
     *
     * \param p_log ignored
     */
    LIBVLC_DEPRECATED LIBVLC_API
    void libvlc_log_clear( libvlc_log_t *p_log );

    /**
     * This function does nothing useful.
     * It is only provided for backward compatibility.
     *
     * \param p_log ignored
     * \return an unique pointer or NULL on error or if the parameter was NULL
     */
    LIBVLC_DEPRECATED LIBVLC_API
    libvlc_log_iterator_t *libvlc_log_get_iterator( const libvlc_log_t *p_log );

    /**
     * Frees memory allocated by libvlc_log_get_iterator().
     *
     * \param p_iter libvlc log iterator or NULL
     */
    LIBVLC_DEPRECATED LIBVLC_API
    void libvlc_log_iterator_free( libvlc_log_iterator_t *p_iter );

    /**
     * Always returns zero.
     * This function is only provided for backward compatibility.
     *
     * \param p_iter ignored
     * \return always zero
     */
    LIBVLC_DEPRECATED LIBVLC_API
    int libvlc_log_iterator_has_next( const libvlc_log_iterator_t *p_iter );

    /**
     * Always returns NULL.
     * This function is only provided for backward compatibility.
     *
     * \param p_iter libvlc log iterator or NULL
     * \param p_buf ignored
     * \return always NULL
     */
    LIBVLC_DEPRECATED LIBVLC_API
    libvlc_log_message_t *libvlc_log_iterator_next( libvlc_log_iterator_t *p_iter,
            libvlc_log_message_t *p_buf );

    /** @} */

    /**
     * Description of a module.
     */
    typedef struct libvlc_module_description_t {
        char *psz_name;
        char *psz_shortname;
        char *psz_longname;
        char *psz_help;
        struct libvlc_module_description_t *p_next;
    } libvlc_module_description_t;

    /**
     * Release a list of module descriptions.
     *
     * \param p_list the list to be released
     */
    LIBVLC_API
    void libvlc_module_description_list_release( libvlc_module_description_t *p_list );

    /**
     * Returns a list of audio filters that are available.
     *
     * \param p_instance libvlc instance
     *
     * \return a list of module descriptions. It should be freed with libvlc_module_description_list_release().
     *         In case of an error, NULL is returned.
     *
     * \see libvlc_module_description_t
     * \see libvlc_module_description_list_release
     */
    LIBVLC_API
    libvlc_module_description_t *libvlc_audio_filter_list_get( libvlc_instance_t *p_instance );

    /**
     * Returns a list of video filters that are available.
     *
     * \param p_instance libvlc instance
     *
     * \return a list of module descriptions. It should be freed with libvlc_module_description_list_release().
     *         In case of an error, NULL is returned.
     *
     * \see libvlc_module_description_t
     * \see libvlc_module_description_list_release
     */
    LIBVLC_API
    libvlc_module_description_t *libvlc_video_filter_list_get( libvlc_instance_t *p_instance );

    /**?@} */

    /** \defgroup libvlc_clock LibVLC time
     * These functions provide access to the LibVLC time/clock.
     * @{
     */

    /**
     * Return the current time as defined by LibVLC. The unit is the microsecond.
     * Time increases monotonically (regardless of time zone changes and RTC
     * adjustements).
     * The origin is arbitrary but consistent across the whole system
     * (e.g. the system uptim, the time since the system was booted).
     * \note On systems that support it, the POSIX monotonic clock is used.
     */
    LIBVLC_API
    int64_t libvlc_clock(void);

    /**
     * Return the delay (in microseconds) until a certain timestamp.
     * \param pts timestamp
     * \return negative if timestamp is in the past,
     * positive if it is in the future
     */
    static inline int64_t libvlc_delay(int64_t pts)
    {
        return pts - libvlc_clock();
    }

    /**?@} */

# ifdef __cplusplus
}
# endif

#endif /* <vlc/libvlc.h> */
